#include using namespace std; typedef signed long long ll; #undef _P #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) //------------------------------------------------------- int N; string S[2002]; ll mo=1000000007; int cost[2020][2020]; ll ret[2020]; ll dp[2020]; const int NUM_=400001; static ll fact[NUM_+1],factr[NUM_+1],inv[NUM_+1]; ll combi(ll N_, ll C_) { if (fact[0]==0) { inv[1]=fact[0]=factr[0]=1; for (int i=2;i<=NUM_;++i) inv[i] = inv[mo % i] * (mo - mo / i) % mo; for (int i=1;i<=NUM_;++i) fact[i]=fact[i-1]*i%mo, factr[i]=factr[i-1]*inv[i]%mo; } if(C_<0 || C_>N_) return 0; return factr[C_]*fact[N_]%mo*factr[N_-C_]%mo; } void solve() { int i,j,k,l,r,x,y; string s; combi(1,1); cin>>N; FOR(i,N) cin>>S[i]; sort(S,S+N); FOR(y,N) { cost[y][y]=cost[y][N]=cost[N][y]=1; FOR(x,y) { cost[x][y]=1; while(cost[x][y]<=S[x].size() && cost[x][y]<=S[y].size() && S[x][cost[x][y]-1]==S[y][cost[x][y]-1]) cost[x][y]++; cost[y][x]=cost[x][y]; } } FOR(y,N) { int co=cost[y][y+1]; for(x=y+1;x<=N;x++) { (ret[x]+=co*combi(N-(y+1),x-(y+1))%mo*fact[x])%=mo; } } FOR(x,N) { for(y=x+1;y